Herbicidal composition



HERBICIDAL COMPMITIDN William H. Jr; Milltown, Arnold 1. Morway,

' Clark, and Jelireyji. Bartlett, Westfield, N. 1., as-

llgnors to Esso Rwearch and Engineering Company, a corporation of Qelaw are No Drawing- H lmllcation December 1954 Serial No. 473,451

Claims. (Cl. 11-416 The present invention relates to compositions for kill ing weeds, and more particularly, to improved composiions which will kill only the weeds to which they are applied and will not have adverse effects upon neighboring growths. Still more specifically, the present invention relates to improved compositions containing, as active herbicidal agents, halogen substitution products of phenoxy carboxylic acids, such as 2,4-dichlorophenoxyacetic acid, 2,4,5 and 2,4,6-trichlorophenoxy acetic acid, trichlorophenoxypropionic acids, their homologues and analogues.

2,4-dichlorophenoxyacetic acid and 2,4,5-trichloro phenoxyacetic acid, the corresponding propionic acids and their derivatives are particularly well known in the art to be effective plant hormone herbicides. Such products are widely used to control weeds and brush that reduce crop yields, block utility rights-of-way, stifle growth of pastures, and detract from the beauty of landscaping and scenery. The acids themselves are usually applied as salt or ester derivatives to the unwanted weeds and brush, either by spraying 6r dusting;-if by spraying, this is often carried out by employing an aqueous solution or emulsion of a water-soluble salt of the acid, the latter being quite water-insoluble. As water soluble salts the 2 and 2,4,5-T, a characteristic so undesirable that in some States the use of esters of these acids is banned.

It is a further object of the present invention to set forth a herbicide composition containing as active ingredient derivatives of 2,4-D and 2,4,5-T which provides herbicidal control of greater extent and longer duration than hitherto found possible.

A still further object of the present invention is to set forth a method of applying a superior herbicidal comform the finished product.

sodium or the amine salts have been used. These compounds are relatively non-volatile, and hence are desirable, but their herbicidal activity is poor in that they are easily washed off treated plants or leached from treated soils. Oil-soluble formulations containing these acids as active ingredient are also available, such as the isopropyl or amyl esters. These materials are also very efl ective herbicides, but their use is accompanied by a severe drawback, their tendency to drift.

"Drifting is a phenomenon which is, to some extent,

.associated with vaporization and volatility and, in the case of weed killers, is the tendency of a composition to wander from the plot of ground to which it is applied over to neighboring fields. Certain crops, notably cotton, are extremely susceptible to 2,4-dichlorophenoxyacetic acid and its derivatives and can be severely damaged by vapors of the weed killer which may drift from fields which are planted with crops tolerant to the weed killer, such as rice, which may have been treated with the chemical for weed control. Most of the esterified forms of 2,4-D and 2,4,5-T, as these weed killers are commonly known, have high drifting" characteristics and are thus hazardous to use in areas where the possibility of crop injury to neighboring 2,4-D non-tolerant crops exist. Furthermore, because of the high volatility of most available esterified forms of 2,4-D, the residual activity of the herbicide sulfers and weed control is not as long-lasting as would be desirable.

It is, therefore, the principal purpose of the present invention to set forth a herbicide and weed killing composition incorporating the halogen substitution products of aryloxyalkyl carboxylic acids which, while being oilsoluble, are/of high potency and do not exhibit the drifting characteristics hitherto associated with esters of 2,4-D

position wherein more complete control is obtained than hitherto.

Other and further objects and advantages of the present invention will appear hereinafter.

Esters and salts of 2,4-D and 2,4,5-T are usually applied to brush in carriers such as .water, oil, or oil/water emulsions. Foliage sprays and basal treatment around trees are the conventional treatment techniques. Frequently these treatments kill only the tops of the trees with the result that new growth subsequently resprouts from the roots. This is probably a result of poor residual properties of the foliage sprays and slow translocation of the chemical into the roots.

In accordance with the present invention, derivatives of 2,4-D and 2,4,5-T, and in particular the esters, are improved in adhesiveness by dispersing grease forming soaps therethrough. The homogeneous solidified esters may be applied as such or may be applied dispersed, preferably in a hydrocarbonaceous or mineral oil to Such products maintain a low volatility of esters, thus minimizing drift, and adhere readily to plant materials.

In further accordance with the present invention, and in a preferred embodiment thereof, the grease base formulation of 2,4D, 2,4,5-T or mixtures thereof are applied to the brush, plant, or tree trunk just above the ground level. The formulations remain where they are applied, and are not washed off by rain or volatilized by heat. This permits-the herbicide to be translocated to the, roots and also produces a girdling effect around the entire circumference of the plant or tree trunk. This cuts off the passage of plant nutrients from the leaves to the roots and vice versa, thus resulting in death of the tree and the roots.

Suitable as the grease making soaps for the practice of this invention are the lithium, aluminum, barium and calcium soaps of C to C fatty acids or fats, including 12-hydroxy stearic acid. The preformed soaps of lithium stearate or lithium hydroxy stearate are preferred because they are of sufficiently low viscosity to give good penetration of the bark or leaf. Their high flash points prevent evaporation and excessive volatility in the hot sun or when aerated during spraying. Lithium stearate is easily dispersed. Lithium hydroxy stearate, also easily dispersible, gives excellent yields (consistency) with small amounts of soap. When the grease is agitated under high shear rates for long periods, it is stable against excessive breakdown to a fluid product.

The soaps and herbicides are suitably dispersed in an animal, vegetable or mineral oil. 01' the mineral oils, generally preferred are Columbian distillates having a viscosity of 60 to 50 SSU at F. and flash points between about 350" to 480 F., SSU being the Saybolt Universal viscosity in seconds. v a

In a preferred embodiment of the present invention, the active herbicide in the grease composition is the reaction product of 2,4-dichlorophenoxyacetic and 2,4,5-trichlorophenoxyacetic acid and certain branch-chained primary alcohols, and specifically the alcohols produced by carbonylation of certain branch-chained olefin fractions.

The ester products are not only of high herbicide potency but also are substantially free of the undesirable Patented Mar. 3, 1959 first stage, oleflns, acted at pressures to form the nature ot the reaction, .eneistheteed-.asinglealcohol or no ,fdriIhZQ InJparticuIar.

"drifting" characteristics hitherto associated with the esters Surprisingly, this drifting is not particularly a function of the molecular weight of the alcohol for, the orresponding straight chain primary alcohol at the same molecular weight has pronounced drifting"'characteristics. This is particularly surprising in view of the well known fact that branch-chain alcohols and esters are subthan the corresponding straight product is hardly everobtained, for the O0 and B, may add on to either of the two carbon atoms of the oleflnic linkage. The process is described in U. S. Patent 2,327,066 to Roelen; 2,504,682. to Harlan, and many subsequent patents.

In accordance with one embodiment of the present inthe. alcohol product obtained when an olefin or olefin mixturehaving at least 6 carbon atoms in the molecule is-employed as feed to the first stage of this reaction is'sesterifled'withthe halogenated phenoxyalkylcarboxylic acidtojform an ester product showing little this characteristic is best shown when .th'ereisernployed as a feedto the Oxo stage a polypropylene or tion boiling in the cue is producedby acid polymerizing of propylene, either alone orpreterably with'va'rying amounts of butylenes.

The reaction product is a'highly branched olefinie mixture, consisting principally of C,,.C-,. C,. and C oleflnic components as well as minor amounts of other olefins. Furthermore, each component or fraction, such as the C traction. consists of a variety of branched heptenes which. after carbonylation and hydrogenation results in a mixture of primary octyl alcohols having a branched chain structure. Thus the polypropylene fraction gives rise to an isooctyl alcohol product consisting of about 4,54limethyl hexanol; of 3,5-dimethyl hexanol; 20% of- 3,4-dimethyl hexanol; the balance are methyl heptanols and trimethyl pentanols.

milarly,-the alcohols obtained by carbonylating the C, fraction is found to consist principally of trimethyl hexanols,

combined with excellent non-drifting characteristics.

' It has further been found that the still pot residue after and herbicidal activity in its ownright, but that it too polymerized propylene-butylene {RC7 heptene and higher range. Polypropyh while the (3,, fraction on carbonylation yields a mixture of tetramethyl nonanols, all, of course, primary alcohols. These alcohol mixtures, on esterification with 2,4-1) or 2,4,5-T all exhibit high weed killing potency may be esterified with the halogenated phenoxyacetic acids to produce an even more powerful weed killer and herbicide which will not drift. In the carbouylation of a Q olefin polymer (i. e. polypropylene) fraction, the bottoms represent about 15-30% of the crude alcohol charged to the distillation zone. The bottoms consist of alcohols, C acetals, C ethers, and minor amounts of esters, ketones and aldols and higher boiling oxygenated organic compounds.

The following examples illustrate the preparation of the 2,4-D esters of these Oxo reaction products. The MJ-Testerscanbemadebysimilarreactions.

' 4 EXAMPLE 1.--PRBPA RATION 01' 15006!- ESIER'OF 2.4-1) 65 g. isooctyl alcohol (from Oxo synthesis), 110.5 g. 2,4-.-D acid and ml. toluene diluent were placed in an esterilication apparatus and the mixture refluxed with stirring until the reaction was complete. 8.2 ml. water were formed. The toluene was then separated from the reaction mixture by vacuum distillation. Unreacted 2,4-D

' acid was separated by treating with aqueous sodium carbonate followed byether extraction of the ester. g.

of ester were obtained (75.5% of theoretical) of 95.5%

purity as indicated by chlorine analysis. The density at the ester was 1.12.

flZXAMPLB 2.PRBPARATION OF 0;. OX0 BSIBI.

. 79 g. C Oxo alcohol, 110.5 g. 2,4-D acid and 100 ml. toluene were reacted in the manner described in Example 1.t llihe yield was 143 g. o 2.

EXAMPLE a-ranrgarrou or o oxo rsrua 93 g. C Oxo alcohol, 110.5 g. 2,4-D acid and 100 ml. toluene were in the 1.-'Theyieldwasl44g.otesterwhichhadadensity EXAMPLE 4.PRBPARATION OF 0;, OX0 ESTER V OF 2,4-D

100 g. C Oxo alcohol. 110.5 g. 2.4-!) acid and 100 ml.

toluene were reacted in the manner described in Example 1. The yield was g.-of-ester of 94% purity as indicated by chlorine analysis. The density was 1.06.

' *gi giFonnulation Ingredients: Percent Lithium soap othydroxystearie aeid...-..-.-.. 10.00 C 010 ester of 2,4-D-..----.--...........- M

Volatility (evaporation rate,

evaporation cut test) 0.335 in 2o hours at 210' P.

The product of Example 5 was diluted 100$with Varsol (naphtha) and homogenized. An excellent grease-like material was formed, which could be diluted further and easily sprayed by mechanical equipment. 1

' EXAMPLE 7 mamas. (powdered hydrogenatedcastcr oil) 90.0% 0,, 0x0 ester of 2.4-1:

olesletwhichhadadenaity.

manner described in Example Penetrations 77 F. mm./

aldolized, dehydrated and hydrogenated to yield the corresponding dimeric alcohols. In each case, the alcohol is esteriiied with 2,4-D, 2,4,5T, or their mixtures.

What is claimed is: 1; A grease composition having herbicidal character- Unworked 300 6 istics which comprises a liquid base comprising a herbi- 50 Strokes 320 cidal liquid ester of a halogenated aryloxy carboxylic w k 1o0,000 strokes 350 acid and an aliphatic primary alcohol having at least 7 PP K P 135 carbon atoms, said liquid base being thickened by hav- 10 ing finely dispersed therein a grease-forming soap selected EXAMPLE 8 from the group consisting of lithium, aluminum, barium and calcium soaps of C to C fatty acids. iiiiicififii'iiifi" A e e e- Prepared by heating to 250 F. and allowing to cool. is-ucs Y i comprises a liquid base comprising herb-b Excellent smooth uniform product of 300 mm./10 cidal hqmd esier a ciflomiated.phenoxy acetic 5 worked penetration. Dropping point,-210 F. and a branched cham ahpilatic Primary Powdered hydrogenated castor oil is one example of at 7 ciu'bon atoms hqmd base bemg thicken! a non-soap thickener. Other non-soap thickeners that by having dlspefsed a 8 gl' fic-formmg soap selected may be employed are carbon black, silica, bcntonites and fmm gmuP cmmsung mhmm' 8111113111111", barium anapulgitcs. and calcium soaps of Q, to C fatty ac|ds.

EXAMPLE 9 3. A grease composition according to claim 2 which is dispersed in a mineral oil having a viscosity of 60 to The formulations below were tested on the coleus 550 SSU at plant, bcing li d as a b d around h t lk, 4. A grease composition having herbicidal character- 'rest Formulation age: Untreated Treated Coleus #1 Treated Coleus #2 h Heal 4.0? Lithium hydroxysteerat 3 neigthym l efl es Droo ing. gziiagzlxgg mg, A afi fifmifi tp s '0 All leaves Dead.

11 .2 East? MM a.. iiiiii l iiii ii ii: I i i i iiie ix 1? 3:38:33: $36523 Witness: eomfifi 1mm A lhl7reflnsdmtnsralollhav1ngavbsos1tyotabout60B.B.U.

EXAMPLE 10 EXAMPLE 11 Small dabs of the herbicidal grease formulations A and B of Example 9 were applied to the stems of poison ivy plants growing in a barberry hedge. In a few weeks all the treated plants were dead. There was no injury to the hedge.

- EXAMPLE 12 The herbicidal grease formulation A of Example 9 was applied as a smear to the stems of dock plants growing next to a fence. 0n the other side of the fence was a neighboring rose garden. In a few weeks the dock plants were dead, while the rose plants were not harmed.

Furthermore, the alcohols that may be employed in the process of the present invention include not only the branch chained alcohols indicated, but also their derivatives and dimers. Thus, the alcohols may be condensed in the presence of an alkaline condensation agent, such as NaOH, to form the dimeric alcohol in accordance with the Guerbet reaction. These dimer alcohols not only possess the branchiness of the original Oxo alcohols but also additional branching due to the condensation reaction.

Dimerized Oxo alcohols may also be produced during the Oxo process itself by the addition of zinc or other reaction modifiers. Also, the Oxo aldehydes may be wherein the C l-1,, group is derived from a C branched chain aliphatic alcohol, said liquid base being thickened by having finely dispersed therein a grease-forming lithium soap of hydroxystearic acid.

laiessneescttedintheflleofthispatent UNITEDSTATBS PATENTS 1,999,524 Molin Apr. 30, 1935 2,284,970 Avery June 2, 1942 2,326,471 Lontz Aug. 10, 1943 2,417,264 Morway et a1. Mar. 11, 1947 2,580,653 Bridgeman Jan. 1, 1952 2,585,875 Swaney Feb. 12, 1952 OTHER REFERENCES Agricultural Chemicals, December 1952, page 26. Botanical Gazette, December 1944, page 218. 

1. A GREASE COMPOSITION HAVING HERBICIDAL CHARACTERISTICS WHICH COMPRISES A LIQUID BASE COMPRISING A HERBICIDAL LIQUID ESTER OF A HALOGENATED ARYLOXY CARBOXYLIC ACID AND AN ALIPHATIC PRIMARY ALCOHOL HAVING AT LEAST 7 CARBON ATOMS, SAID LIQUID BASE BEING THICKENED BY HAVING FINELY DISPERSED THEREIN A GREASE-FORMING SOAP SELECTED FROM THE GROUP CONSISTING OF LITHIUM, ALUMINUM, BARIUM AND CALCIUM SOAPS OF C12 TO C22 FATTY ACIDS. 